A nonequivalent control group design is being employed to evaluate the relative efficacy of a blood pressure control system designed to change people's health beliefs, knowledge about high blood pressure, and increase the number of hypertensives under adequate treatment. The blood pressure control system entails outreach to clients and providers, screening for high blood pressure, referral of people with risk-level readings to physicians, and follow-up with both clients and their physicians. In addition, a set of staged experimental interventions will be undertaken in a group of hypertensives to test the effects of different follow-up strategies with clients. Experimental treatments included printed messages, telephone reminders, and nurse visits.